(a) Field of the Invention
The present invention is related to a structure of filter of a respirator, and more particularly, to one that improves smoke and toxicity filtration effects by increasing the area and time for gas to contact the filter.
(b) Description of the Prior Art
As illustrated in FIGS. 1 and 2 of the accompanying drawings, a respirator filter 1 generally available in the market is comprised of fireproof fabric, non-woven fabric and active carton fabric laminated in sequence to filter toxic gas passing through the filter 1 to prevent a person wearing the respirator from suffocation when trying to escape from a fire. Whereas, filter effect is significantly affected by the area of use and number of layer of the filter materials used, the effectiveness of the respirator filter in practical use is pending verification. However, as taught by theories, active carbon, chemical and catalyst are required to effect removal of hazardous gas. In a cartridge type of filter as illustrated in FIG. 2, it produces better filter effects than the laminated filter described above does. The primary cause is that the gas travels over a longer passage (8xcx9c15 cm) in the cartridge type of filter than the laminate filter does (0.8 cm). That is, it takes longer time for the gas to leave the cartridge. Usually when one wears a respirator, his respiration is drastically reduced to a fixed range, resulting in drastic deterioration of the filter effect. Accordingly, the laminated filter actually fails to achieve its purpose of safe protection.
The primary purpose of the present invention is to an improved respirator filter by extending the time the gas flowing through each layer of the filter to enhance filter effects.
To achieve the purpose, a lamination of the filter is provided containing layers of fire-proof fabric, static fibers, active carbon fibers and non-woven filter cotton interlaced with multiple airflow guides so that the gas inhaled creates internal and external circulation as directed by those guides to increase area and filter time for the gas to contact the filter, thus to improve smoke and toxicity filter effects.
The airflow guide is provided at its center a hole, or in its peripheral multiple holes so to allow the airflow to concentrate passing through the central hole or dissipate towards the peripheral of the airflow guide to create air conduction, thus to increase the length of filter time.
Finally, those airflow guides are interlaced provided among the layers of various filter materials the filter to create air conduction.
The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.
Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.